The present invention relates generally to the field of cleaning a gas stream and more particularly to a method and apparatus for removing particulates and absorbing selected gases from a gas stream by mixing a gas with a liquid to wet the particulates and absorb the selected gases to discharge a cleaned gas in an economical manner.
It is very often desirable to clean a gas stream of particulates and/or undesirable gases. It is sometimes desirable to remove particulates or selective gases for capture or disposal from a gas stream by absorption or mixing with a liquid. It is also becoming more desirable and popular to clean air in domestic settings, particularly the removal of spores, bacteria, and viruses due to the current biological threats by terrorists. Other domestic pollutants include, but not limited to, allergens such as pollen, mites, pet dandruff, hair and dead skin and dust, and gases such as carbon dioxide, carbon monoxide, and other auto emissions.
Several methods are currently used to clean or partially clean gases such as air in a domestic setting. Some of the most common methods of xe2x80x9ccleaning airxe2x80x9d are the utilization of filter systems, electrostatic devices, and venturi scrubbers. Filter systems require frequent cleaning and electrostatic devices and venturi scrubbers are limited in the quantity of gas being processed economically.
Viruses, bacteria, spores, small particulate and some small insects such as some small baby spiders, often float in air currents and even circle the earth. It is said that such minute living beings can travel to outer space and live for over one thousand years, even though exposed to extreme temperatures and radiation. It is therefore not reasonable to assume that the gravitational force of only one gravity can totally and efficiently remove such minute beings and particulate from the domestic air that we breathe. Yet, it is very easy to provide a centrifuge that can produce a gravitational force of thousands of gravities.
It is a desire to provide an improved method and apparatus for removing particulates and selected gases from a gas stream by flowing the stream through a centrifuge. It is a further desire to convey a stream of gas and liquid through a specially designed venturi throat at a high velocity and impact it with the surface of an economically produced stream of flowing liquid. It is a still further desire to provide a centrifuge that can continually centrifugally remove small particulate from a gas and has an economical method for continually removing such particulate that collects on the inside centrifuge wall.
A system and method of cleansing a gas of undesired particulate, aromas, and gases of the type utilizing a liquid to wet the particulate and absorb selected gases from a gas stream is provided. A centrifuge cylinder is used and a liquid stream is provided to remove the centrifuged particulates from the inside wall of the centrifuge cylinder. The gas scrubber of the present invention including a container having a bottom wall and a top wall, interconnected by a side wall for containing a liquid therein having a surface positioned below the top wall that provides a space between the surface and the top wall. The top wall is provided with an opening, and a rotatable shaft is vertically mounted above the top wall and down through the midsection of the opening and down through the midsection of a rotatable vertically mounted siphon pipe that is positioned inside of a rotatable vertically mounted centrifuge cylinder. The siphon pipe and the cylinder are attached to the shaft so that the pipe and cylinder are rotated by the shaft. The cylinder top inlet opening is positioned proximate the top wall inlet opening and the cylinder bottom outlet opening, larger than the cylinder inlet opening, is positioned proximate the upper portion of a venturi throat that is connected to the cylinder outlet. The siphon pipe bottom inlet opening is positioned below the liquid surface to allow the liquid to flow to the inside of the siphon pipe and to rotate therewith. The siphon pipe top outlet opening is larger than the bottom inlet opening and is positioned proximate the cylinder inlet opening so that liquid flowing from the siphon pipe flows to the cylinder and out the cylinder outlet. Fan blades are positioned in the cylinder to draw gas from the outside of the container and through the cylinder.
In operation, the rotating liquid inside the siphon pipe is centrifugally forced up and out the siphon pipe outlet and to the blade walls and the inside wall of the cylinder. Liquid flows down the blade and cylinder walls, out the cylinder outlet, and through the venturi throat at a high velocity. Gas is drawn from the cylinder inlet, by the rotating fan blades, and flows out the cylinder outlet and through said throat with said liquid. The gas, and particulates in the gas, is mixed with the liquid as it comes in contact with the liquid flowing down the walls of the blade and the inside of the cylinder. Heavier particulates in the gas are centrifugally forced to the inside cylinder wall and liquid wetted when coming in contact with the flowing liquid. The particulates and selected gases in the incoming gas stream are additionally wetted and absorbed in the high velocity liquid stream as they flow together through the channel throat to the space.
The apparatus is provided with a way to allow the scrubbed gas to flow out of the container with entrained liquid in the scrubbed gas to be centrifugally removed and a way to replace liquid removed by the operation.
The apparatus is also provided with a way to cause said liquid surface to slope upward in the area of the throat outlet and cause the stream of high velocity liquid and gas mixture to come in contact and impinge on said liquid surface. This further liquid wets the particulates and provides a quieter operation.
Alternate forms of the apparatus are taught including an apparatus having an additional siphon pipe to flow liquid to the bottom of the cylinder, as well as the top, an apparatus having only one siphon pipe at the bottom, and an apparatus having no siphon pipe. Also different forms of the channel and throat are shown.
The main advantages of the present invention include an apparatus and method for cleaning a gas stream by wetting it with a liquid by utilizing a combination of forces including: impacting the surface of a flowing liquid stream with the stream of gas to be cleaned; centrifugally subjecting the gas stream to a very high gravitational force to cause heavier particulates and molecules to gravitate out and mix with a flowing liquid stream; flowing the mixture of gas and liquid at a high velocity through a restricted throat thereby causing a venturi scrubbing of the gas stream; and forcing the mixture stream out of the throat to contact and impinge the liquid surface and have a portion of the stream to submerge beneath the liquid surface to further wet the particulates and gas.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of preferred embodiments of the invention that follows can be better understood. Additional features and advantages of the invention which form the subject of the claims of the invention will be described hereinafter.